There are known in the prior art two general types of ice makers. The first of these which produces what is known in the art as flake or chip ice rather than hard ice includes an auger or the like which scrapes ice crystals from a tubular freezing surface and feeds the resultant slush ice outwardly through a die or the like to form flake or chip ice. Alternatively, a cylindrical freezing chamber can be employed and scraper blades on the outside of the chamber remove the ice crystals. In all ice makers of this type this chamber is vertical and of tubular or cylindrical shape. While ice makers of this type produce ice on a continuous basis, they embody the defect that the tubular evaporator configuration is mechanically weak and it requires various bearings and water seals. It is relatively costly to produce. In addition, the quality of ice produced on ice makers of this type is not consistent but is a function of the ambient temperature and the temperature of the incoming water and of the condition of the refrigerating equipment.
The other type ice maker known in the art is a "cube" ice maker in which water in a container is subjected to the action of a refrigerant. While some of the cube ice makers employ flat plate type evaporators, none of them produce ice on a continuous basis. That is to say, the freezing cycle is carried on until ice of the thickness of about one quarter to one half inch is formed and is then interrupted. Following interruption of the freezing cycle a harvest or defrost cycle is started. Thus, ice makers of this type do not produce ice on a continuous basis. While the ice is of high quality, the machine is extremely inefficient owing to the inherent insulating property of the ice itself. Stated otherwise, a relatively great refrigerating effort is required to produce ice of any appreciable thickness.
We have invented a plate type ice maker which overcomes the defects of ice makers of the prior art. Our plate type ice maker is adapted to produce chunks of hard ice on a continuous basis. It is more rugged than are auger type ice makers of the prior art. It is less expensive to manufacture than auger type ice makers. It is more efficient than are cube type ice makers of the prior art. It does not require the alternate freeze and harvest cycles of cube type ice makers of the prior art.